Vessel for treating fibrous material



March 15, 1932. T 4. J. DE LA @ZA SR 1,849,866

VESSEL FOR TREATING FIBROUS MATERIAL Filed Dec. 16, 1929 /@4; ATTORNEYSPatented Mar.'15, 1932 UNITED STATES JOAQUIN JULIO DE LA ROZA, $3., OFTUINUGU, CUBA VESSEL FOR TREATING FIBROUS MATERIAL Application filedDecember 16, 1929. Serial No. 414,610.

This invention relates to a vessel for treating fibrous material and,more particularly, to a vessel designed for treatin annual plants,

grasses, etc., with chemicals and heat, in the manufacture of cellulose.

The invention has for an object to provide such a vessel that may becharged and, emptied with economy and expedition.

Another object is to provide such a vessel that may be discharged at theend of the treating step without the necessity of waiting for it tocool.

Another object is to provide such a vessel which may be charged by meansof baskets or the like adapted to contain the material and havingsubstantially the same cross sectional size as the vessel, lesssufiicient clearance to allow for the insertion and removal of thebaskets.

' Another object is to provide such a vessel that is jacketed for thereception of a temperature controlling medium in order to attain andmaintain the desired temperature of treatment, without obstructing theinterior of the vessel and without bringing the heating medium incontact with the contents.

Another object is to provide such a vessel that includes means forguiding the baskets during their insertion and removal and forpreventing injury which might result from contact of the baskets withthe walls of the vessel.

Another object consists in providing certain improvements in the form,construction and arrangement of the several parts, whereby the abovenamed and other objects may effectively be attained.

A practical embodiment of the inventlon 1s represented in theaccompanying drawings, in which i Fig. 1 -represents a vessel;

Fig. 2 represents a vertical section taken in the plane of the line11-11 of Flg. 1, looking in the direction of the arrows;

top plan view of the Fig. 3 represents a detail section, on an en- P gthe guiding means and its fastening dev ces. The vessels, known asdigesters,

lar ed scale, through one of hereinsuch as sugar cane, cornsta s, straw,

' and disadvantages above recited.

before commonly employed for the treatment of vegetablefiber under theaction of chemi- 1 cal and heat to produce cellulose, have beenrestricted in cross sectional size at one or both ends and provided withopenings for'charging and discharging, which openings have been of asize very much smaller than the cross sectional size of the interior ofthe vessels. This has been true whether the vessels have had an openingat only one end or at 00 both ends; and it may be specifically pointedout that, while these vessels-are frequently from six to twelve orfifteen feet in diameter,

a charging or discharging opening of two and one-half to three feet indiameter has 66 been the largest employed.

p These vessels, while apparently satisfactory for use in the productionof cellulose from wood and the like by old and well known processes,have not been very success- 70 ful in the production of cellulose fromannual plants, particularly with respect to discharging the vesselsafter treatment, because the matting or bridging of the fibrous materialhas required workmen to enter the vessels subsequent to a treating stepand remove the charge. This procedure requires delay while waiting forthe vessels to cool; it necessarily involves a slow rate of discharge;entails labor expense; and compels the workmen to operate underunhealthful conditions; as well 'as giving rise to other uneconomical orunsatisfactory factors.

The matting and bridging difficulty is accentuated when the material isonly partly pulped in a given treatment, and is still further increasedwhen manufacturing cellulose from such annual plants, for instance, assugarcane. This last named material, unless fully cooked so that it iscompletely pulped, has a particular tendency to clogging the digestersand giving rise to the difliculties It has been suggested to so cook anddilute f 5 the material being treated that it might be umped or mightflow from the vessel when desired, but this has not solved the problemand not only involves expense in itself but also prevents the digestersfrom being fully 1 charged with the material as the economics of themanufacture demand.

Such prior vessels have also been arranged to have a. temperaturecontrolling medium, such as steam, applied thereto either by directinjection or by traversing a coil located within the vessel. Sucharrangements have been found to be objectionable because, in the firstcase, the injection of the steam brings it in direct contact with thecontents and tends to injure the same. Further, the increment of steamserves to dilute the strength of the chemical solution employed in thecooking treatment. In the case of the use of a coil, the interior of thevessel is partially obstructed so as to handicap charging anddischarging and there is also a tendency to excessive local heating ofthat portion of the charge in contact with the coil. Furthermore, inconnection with both of these prior practices, it has been extremelydiflicult' accurately to maintain a predetermined temperature of thecharge as a whole, which is a very important factor. I

My invention overcomes all these previous diiiiculties anddisadvantages, and has desir able features of its own. Briefly stated,the invention comprehends so constructing a vessel of this characterthat its opening for charging and discharging is of substantially thesame cross sectional area as the body of the vessel, and providing thevessel with a jacket for the reception of a temperature controllinmedium, such as steam or hot water. Pref%rably, the vessel issubstantially cylindrical throughout, and it-may be noted that myinvention is applicable whether the vessel be of the stationary or ofthe rotary type.

Referring to the drawings, the body of the vessel is marked 1, and itmay be composed of steel, iron, chrome nickel, or any other suitablematerial. If material is used that is not resistant to the chemicalaction engendered by the treatment, the interior of the vessel should belined or coated with some material such as lead, chromium or cadmium.Brick of suitable character may also be employed. These materialsandtheir capacities for resisting chemica actions are well known to thoseskilled in this art.

The vessel is shown as cylindrical and of the same crosssectionthroughout. Its upper end is open and provided with an annularflange 2 for the reception of a dished cover 3 that is supplied with aring 4cfor the purpose of handling the same, as by tackle or otherwise.The ring is preferably welded to the cover.

This cover 3 is also composed of suitable material for resisting thechemical action, and its periphery is arranged to be secured to theflange 2 by bolts 5 that traverse the same.

The upper and lower portions of the vessel may be provided with suitableinlets, outlets, or vents represented by 6, 7, which parts are alsopreferably composedof similar reshould likewise be resistant to thechemical action.

It will be understood that the provision of these last named parts is amatter of choice and engineering selection in any particularmanufacturing plant and that the illustration and description just givenofthe parts 6--8 is intended conventionally to represent such detailswhich may be varied to suit any particular requirements withoutaffecting my present invention.

The body of the vessel is embraced by a jacket 9- which maybeconstructed in any approved manner as, for instance, by welding. Thesaid jacket is preferably composed of sheet metal of the samecomposition as the vessel and correspondingly resistant to the chemicalaction, and it may be secured at its bottom and top to the body of thevessel by welding.

In order to arrange for the circulation of a temperature controllingmedium, such as hot'water or steam, within the jacket, the latter isfitted with inlet and outlet, 10, 11, which may be of conventional formand interiorly threaded for the reception of pipes.

As it is contemplated that this vessel is to be charged and dischargedby the use of baskets of material, which baskets are in-' tended to belowered into and'removed from trolling the movement of the baskets asthey are inserted and removed and also prevent contact of the basketswith the wall of the vessel, which contact might result in injury. Asshown in, Fig. 3, the said rails are preferably similar to small sizedrailroad rails and should be composed, as in the case of the abovedescribed parts, of material which will not be injured by the chemicalaction involved in the process carried on in the vessel. The said railsare removably secured in place by stud bolts 13, welded to the innersurface of the vessel 1, and provided with lugs '14 and nuts 15 forclamping the flanges of the rails. This arrangement permits the readyinsertion and removal of the rails and thus not only facilitatesconstruction, but

allows for repair and replacement when In operation, the vessel mayconveniently be charged by packing the material in baskets, or the like,whichare of substantially the same size as the interior of the vessel,with the necessary allowance for the rails 12 and for clearance. Thebaskets may be lowered into the vessel by crane or other suitable means,and rest on a rack or upon the bottom of the vessel during thetreatment. At the end of the treatment, the cover may be re-- moved byloosening the bolts 5 and lifting the cover away with tackle, and thebasket containing the material may be lifted out of the vessel bysimilar means. This last named means, as well as the baskets, should becomposed of such material or be so treated as to resist the chemicalaction involved in the process carried on in the vessel. This manner ofcharging and discharging is very effective and expeditious, and tendslargely to overcome the previous disadvantages inabove recited.

The provision of the enlarged opening at the top of the vessel, which isin diameter at least more than one-half of the diameter of the body ofthe vessel and, preferably, equal to the diameter of the vessel, enablesthe rapid and effective charging and discharging of the vessel withoutthe previous difiiculties; while the provision of the jacket for thecirculation of the temperature controlling medium enables apredetermined temperature to be exactly attained and maintained, withoutany obstruction of the vessel, without any local overheating of thecharge, and without any dilution of the chemical solution. While the jacketing feature is applicable to vessels of other form, and whetherthey have relatively large or relatlvely small openings, it is ofparticular advantage in connection with the form of vessel shown in thisapplication, because it leaves the interior of the vessel free for theinsertion and removal of a large and comparatively closely fittingbasket of material. while providing adequate means for supplying uniformtemperature throughout the charge. 1

It will be understood that various changes may be resorted to in theform, material, construction, and arrangement of the several partswithout departing from the spirit and scope of my invention; and hence Ido not intend to be limited to the details herein shown and describedexcept as they may be included in the claim.

What I claim is:

A vessel of the character described, which is fitted to be charged anddischarged by the insertion and removal of material-containingreceptacles, comprising a body provided with a charging opening havingan area substantially the same as the cross sectional area of the body,a cover for said charging opening, means for removably securing thecover in position, a jacket surrounding the body for containing atemperature controlling medium,

and vertically disposed guide rails located on the inner walls of thevessel for preventing contact between the receptacles and the walls ofthe vessel and for guiding the receptacles during insertion and removal.

In testimony that I claim the foregoing as my invention, I have signedmy name this 12th day of December, 1929.

JOAQUIN JULIO do In ROZA, Senior.

here-

